As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Imaging apparatuses, for example printers, copiers, and facsimile machines, are often used alone and/or in combination with information handling systems to print latent images (e.g., text and/or pictures) on a recording medium (e.g., paper, transparencies, and/or any other suitable medium) using an imaging medium (e.g., toner, ink, and/or other suitable medium). Modern imaging apparatuses may include, without limitation, toner-based imaging apparatuses and inkjet imaging apparatuses.
A toner-based imaging apparatus may use a laser, light-emitting diode (LED), and/or other suitable electromagnetic energy source to sensitize selected regions of a photoconductive drum. Charged toner particles may adhere to the selected regions of the photoconductive drum, and then may be transferred from the drum to the recording medium. The toner particles may be fused to the recording medium with heat and/or pressure.
On the other hand, an inkjet imaging apparatus may use a spray nozzle to spray small, precise droplets of ink onto a recordable medium. Often, the droplets may carry a slight electrical charge. Accordingly, the placement of a droplet on the recording medium may be determined by the charge of a cathode and electrode between which the droplet moves toward the recording medium.
The imaging medium (e.g., toner, ink, and/or other suitable medium) used in an imaging apparatus may be supplied from a cartridge, which may also be known as a “toner cartridge” or “ink cartridge” depending on the imaging medium used. In some instances, an imaging medium cartridge may comprise one or more disposable portions that may be discarded and/or replaced after the volume of imaging medium in the cartridge has been substantially depleted from use.
Because the volume of imaging medium in a cartridge may be depleted over time, it is often necessary to gauge the remaining volume of imaging medium and convey such information to a user, so that the user may replace a substantially depleted cartridge. However, conventional approaches for determining the volume of remaining imaging medium in a cartridge are often inaccurate, particularly in toner cartridges used in toner-based imaging apparatuses. Accordingly, due to these inaccuracies, imaging medium cartridge manufacturers may often “overfill” the cartridges with more imaging medium than the stated volume in order to maintain customer satisfaction. Because of this “overfill,” cartridge manufacturers may experience revenue loss proportional to the amount of overfilling.
One approach to determine the volume of remaining toner in a toner cartridge uses a load cell to measure the weight of toner remaining in the cartridge, as discussed in U.S. Pat. No. 6,246,841. However, this approach requires a load cell and corresponding circuitry to measure the toner weight, and thus may be prohibitively expensive for many applications.
Another approach uses “pixel counting,” which includes determining the number of pixels printing on a recording medium, in order to determine the volume of toner remaining, as discussed in U.S. Pat. No. 6,456,802. However, this approach may be inaccurate due to indeterminable flow characteristics of toner in a cartridge.